"To those struggling with anxiety, OCD, depression: I know it's mad annoying when people tell you to exercise, and it took me about 16 medicated years to listen," Dunham wrote. "I'm glad I did. It ain't about the ass, it's about the brain."

Dunham isn't the only celebrity who wants the world to know she's a fan of exercise. From gym selfies to scenic hikes, these famous women are all about getting their sweat on.